Achieving microarcsecond or even nanoarcsecond resolution in astronomy is highly challenging due to technical limitations, yet it is an area of active research and development.
Microarcsecond resolution, which is a millionth of an arcsecond, is achievable with the right technological advancements. Radio astronomy has made significant strides in this domain with Very Long Baseline Interferometry (VLBI). VLBI involves combining data from several radio telescopes spread across vast distances, effectively enhancing the resolution of the observations over what any single telescope could achieve. Projects such as the Event Horizon Telescope, which released the first image of a black hole, have successfully reached microarcsecond scales by using this technique.
Optical and space telescopes also aim for higher resolution, with innovations like adaptive optics that can compensate for atmospheric disturbances and space-based telescopes that avoid atmospheric blurring completely. Future missions, such as those involving interferometric techniques in space (e.g., the planned LUVOIR or HabEx missions), are promising for achieving microarcsecond precision.
Nanoarcsecond resolution, being a billionth of an arcsecond, is far more challenging and remains mostly beyond current capabilities. However, specific techniques, such as gravitational wave astronomy and advanced VLBI with even broader baselines, could push the boundaries towards this extreme precision in the future. Achieving such precision would require not only technological innovations but also significant advancements in data processing, noise reduction, and signal detection.
Overall, while achieving nanoarcsecond resolution remains beyond reach with current technology, microarcsecond resolution can be and is being approached in some fields, particularly radio astronomy. The pursuit of these resolutions will likely continue to drive the development of innovative techniques and technologies in astronomy.